Macular degeneration, or Age Related Macular degeneration (AMD) is a degenerative disease affecting people over 55 year of age. It becomes much more common as we age and is the leading cause of severe, irreversible, vision loss in patients over 60. The exact cause is unknown, but several risk factors, including smoking, genetics, and age are associated with AMD. There are three stages of AMD, Early, Intermediate, and Advanced.
Early AMD is characterized by changes in the appearance of the retina when examined by a retinal specialist. These patients have not lost vision and are at low risk for progression. Observation and monitoring alone are recommended.
Intermediate AMD is characterized by high risk changes in the appearance of the retina when examined by a retinal specialist. These patients have not lost vision but are at high risk for progression. The National Institutes of Health (NIH) conducted two five year clinical trials to evaluate the effects of high dose vitamins on patients with AMD, the Age Related Eye Disease Study (AREDS) and AREDS2 studies. These studies showed a small, but significant decrease in the risk of progression from Intermediate AMD to Advanced AMD in patients who took high dose vitamins. For this reason, we recommend close monitoring and taking the AREDS or AREDS2 formula daily. Only a retina specialist experienced in grading AMD can diagnose you with intermediate AMD.
Advanced AMD is the final stage of AMD when patients loose vision. There are two causes of vision loss in Advanced AMD.
First, the layer of cells beneath the retina can slowly disappear. This leads to a blind spot, or scotoma, that slowly increases in size. If the blind spot involves the fovea, or center of the macula, then good central vision is lost. This is often referred to as dry AMD but is more properly called geographic atrophy. At this time there is no treatment for geographic atrophy, but clinical trials are currently going on to find a treatment for this condition.
The second type Advanced AMD is neovascular, or wet AMD. In neovascular AMD new abnormal blood vessels grow under the retina. These blood vessels can leak fluid causing edema (swelling) in the retina, fluid under the retina, or detachments of the layer of cells under the retina, called the retinal pigmented epithelium. In the worst cases, these blood vessels can bleed under the retina causing acute vision loss and eventual scarring. Neovascular AMD causes sudden vision loss with symptoms or distortion (straight lines look bent or wavy) blurry vision, and blind spots. The good news is that there are effective treatments for neovascular AMD that can stop the progression of vision loss, or even improve vision in some cases (40%). If you or someone you know has symptoms of nonvascular AMD, you should see treatment from a surgical retinal specialist immediately.